Caveats in Using Trotter and Gleser's (1958) Asian Equations for Stature Estimation

Abstract

: Trotter and Gleser's (1958) Asian equations have most frequently been used for stature estimation of Korean skeletal remains. However, limitations or caveats in using those equations have rarely been argued. This study reviews five issues frequently overlooked in applying the equations and interpreting the outcomes.First, Trotter and Gleser (1958) multiply the standard errors by 2 to obtain the 95% prediction interval (PI). However, there is discrepancy between their calculation and actual PIs, and thus correct method for PI calculation is recommended. Secondly, given the uncertainty about the tibia length measurement, there is a possibility that the tibia-related equations yield biased estimates. Thirdly, since a mathematical error was incorporated in the development process of the combined equations, caution should be taken. Fourthly, extrapolation may cause additional unexpected error in applying regression equations. Therefore, it is necessary to check if a target sample falls within the reference sample range prior to using the equations. Lastly, applying Trotter and Gleser's (1958) equations to female samples should be avoided because they produce highly biased estimates.The issues discussed in this study will contribute to reducing potential errors associated with application of these equations, and eventually enhancing accuracy of the final stature estimates. If errors are anticipated but unavoidable, discussions about the potential errors should be made to minimize misunderstanding about the outcomes.

Trotter and Gleser’s (1958) equations outperform Trotter and Gleser’s (1952) equations in stature estimation of the US White males

“…As Jantz and colleagues [ 30 , 31 ] raised the issue of possible mismeasurement of the tibia in Trotter and Gleser’s 1952 study, the accuracy of the tibia-related equations has been debatable [ 17 , 41 ]. Jantz and colleagues [ 30 , 31 ] speculated that, unlike the description presented in Trotter and Gleser [ 14 ], Trotter measured the maximum length of the tibia excluding the malleolus resulting in the overestimation of statures when the malleolus-included tibial length is plugged into the tibia equation.…”

“…In fact, the stature estimation tool built into FORDISC, a forensic anthropological analysis software popular among forensic practitioners, is based on the Trotter and Gleser’s 1952 dataset, not their 1958 dataset, to estimate statures of the 20th century (20C) Whites and Blacks [ 20 ]. However, a standard error associated with a certain regression equation is not necessarily a measure of its performance as it is not a predictive estimator but simply a descriptive indicator of the overall discrepancy between the actual and estimated values in a dataset used for the equation development [ 17 , 21 ].…”